package com.hao.netty.chapter02.aio;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.Date;

/**
 * @Description //TODO
 * @Date 2020/1/11
 * @Author songhao
 **/
public class ReadCompletionHandler implements CompletionHandler<Integer, ByteBuffer> {

    private AsynchronousSocketChannel channel;

    @Override
    public void completed(Integer result, ByteBuffer attachment) {
        attachment.flip();
        byte[] body = new byte[attachment.remaining()];
        attachment.get(body);
        try{
            String req = new String(body,"UTF-8");
            System.out.println("The time server receive order : " + req);
            String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(req) ? new Date(System.currentTimeMillis()).toString() : "BAD ORDER";
            //写结果信息
            doWrite(currentTime);
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    private void doWrite(String currentTime) {
        if(currentTime != null && currentTime.trim().length() > 0){
            byte[] bytes = (currentTime).getBytes();
            ByteBuffer writeBuffer = ByteBuffer.allocate(bytes.length);
            writeBuffer.put(bytes);
            writeBuffer.flip();
            channel.write(
                    writeBuffer,
                    writeBuffer,
                    new CompletionHandler<Integer, ByteBuffer>() {
                        @Override
                        public void completed(Integer result, ByteBuffer buffer) {
                            //如果没有发送完成，继续发送
                            if(buffer.hasRemaining()){
                                channel.write(buffer,buffer,this);
                            }
                        }

                        @Override
                        public void failed(Throwable exc, ByteBuffer attachment) {
                            try{
                                channel.close();
                            }catch (IOException e){
                                e.printStackTrace();
                            }
                        }
                    });
        }
    }

    @Override
    public void failed(Throwable exc, ByteBuffer attachment) {
        try{
            this.channel.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    public ReadCompletionHandler(AsynchronousSocketChannel channel) {
        if (this.channel == null) {
            this.channel = channel;
        }
    }
}
